Fix extra information from web source

I am having some trouble fixing the metadata tags of my music collection by using as the web source.
For example, when I search for the "Notting Hill" soundtrack, the actual data returned is:
"From the heart - Another Level (bonus track)"

I set the "Compilation" option to %Title% - %Artist%.
But this results in the metadata to be set as:
Title: From the heart
Artist: Another Level (bonus track)

which is obviously wrong.

Is there a way to fix such issues?

I haven't got a clue what you are talking about.
AFAIK if you use the web source it uses the ALBUM as search criterion. So where do you set a compilation option?
Please explain your workflow in more details.

Yes, with as the web source, I enter the ALBUM name and MP3Tag fetches the metadata.
It then presents me with a dialog box where I can match the returned metadata with my files ("Adjust Tag Information"). See attachment.

As I mentioned in my previous post, the actual data returned is of the form:
Title = "From the heart - Another Level (bonus track)"

At the lower left corner of this dialog box is a button called "Utils". On clicking it and selecting the "Compilation" option, I enter the format as "%Title% - %Artist%". This results in the metadata to be set as:
Title = From the heart
Artist = Another Level (bonus track)

The "(bonus track)" should be appended to Title and not Artist.
How can I fix this?